Method of forming integral tubular projections on a sheet of metal



Jam, 115 1929.

J. KARMAZHN METHOD OF FORMING INTEGRAL TUBULAR PROJECTIONS ON A SHEET OF METAL Filed Feb. 17, 1926 k. WW

HIIII III[ lllll INVENTOR JOHN KARMAZIN atented Jan. 1929.

I PATENT ()F FI CE.

JOHN KARZl VIAZIN, 015 DETROIT, MICHIGAN.

METHon or FORMING INTEGRAL TUBULAR PROJECTIONS 01v a SHEET or METAL.

Application filed February This invention relates to a method of manufacturingradiators of the type dlsclosed in my prior co-pendmg application,

Serial No. 641,850, filed May 28, 1923.

-In said application, I have disclosed a method of making radiators whlch consists in passing a strip of metal through a forming machine which deforms the strip producing therefrom rows of lntegral tubular projections. The' tubular pro ect1ons, according to said application, are formed in a series of eight forming dies, the first of which produces a shallow depression in the strip-of such diameter-that substantially all of the metal required to form the. final projection lies in the depression and the succeeding dies gradually deepen and reduce the diameter of the depression to form the finished tube, working the healthy uns trained metal into the tube walls, returning the strained outer edge of the first depression to the plane of strip, w1thout substantially thinning or weakening the metal in the original sheet or in the tube walls.

or weakened.

' Various other objects and advantages will ,appear as the" description of the invention proceeds. h

Referring to the drawings, which lllllS- trate one of the preferred forms of embodiment of the invention,-

Fig. 1 is an enlarged sectional elevation of a portion of a radiator element forming machine showing the dies.

Fig. 2 is'a portion ,of a strip of metal partly formed into an element.

Fig. 3 is a section on the 11118 33 of Fig. 2.

In the form of embodiment of the invention illustrated in Fig. 1, the forming dies consist of downwardly extending plunger tubular projections.

17, 1926'. Serial No. 88.739.

members 10, 11 and 12 which are connected to a movable head 21 and engage respectively with the stationary die members of matrices 1.3, 14 and 15, set into the base 22. The line AA indicates the diaiding line of the upper and lower die and also defines the normal plane of the strip or sheet passing through the dies. The initial forming die 13 is providedwith an annular portion 16 raised above the dividing line AA of the die, about midway toward the center thereof, the outer surface 17 of which slopes downward in a gradual curve toward the dividing lineof the: die. The raised portion has in its center a depression 18 whose bottom is above the dividingline AA and whose diameter is slightly larger than the bottom diameter desired in the finished I A hole '19 in the ma.- trix 13 is adapted to receive the ejector pin 20, urged upward by a spring 20, which raises the sheet from the die or matrix following each forming operation. The intermediate die member 14 has a depression 23 below the line A-A, which is intermediate the diameter of the depression 24 in the last die member 15, and the diameter of the de-' pression 18, and is not quite so deep as the depression 24. These dies 14 and 15 are also adapted to receive respectively ejector pins 25 and 26 provided with springs 25 and 26, which raise the strip of metal out of the dies after the operation of the die. A punching die (not shown) is provided for punching out the bottom of the depressions to form the tubular projection similar to the manner shown in my co-pending applications above referred to.

I In the operation of my processa strip of 'metal 27 is fed to the diesfrom left to right and the first pair of dieslO and 13 deform the metal into a raised annular portion 28 with a depression 29 in the center. The strip is then moved until the first deformation is centered between the intermediate dies 11 and 14 which come together and press the first deformation into the deeper depression 30, located entirely below the plane of the sheet. At the same time the first dies 10 and 13 make another deformation 2829 on the strip. The strip is then moved and the second depression 30 centered between the last pair of dies 12 and 15 and when the dies come together the depression 30 is deepened and reduced in diameter to form the projection 31. At the same time an intermediate depression has been formed by the intermediate dies and another initial deformation byfthe first dies, the three sets 5 of dies operating simultaneously to complete one tube and perform thetwo preliminary steps at each depression of the head 21. Following the completionof the depression 81, the bottom of the projectionsmaybe punched out by punches carried by the upper 7 die member 21 to'forni completed tubular projections 32. By'r'aising substantially'all of the metal necessaryfor the tubular projection. above the lane of the strip in the first operation and forming an initial depression 29 therein of about the size and 'shape of the bottom ofthe final projection, the desired final shape and size of projection may be formed in a much smaller num-v her of steps than is possible where the initial depression is formed below the plane of the strip, as described in my prior application and heretofore practiced. While I have illustrated and described a preferred form of embodiment of my invention, it is to be understood that various modifications and changes may be made without departing from the spirit of the.

invention or the scope of the claims.

I claim:

1. A method of forming a sheet metal strip with a series of tubular projections-on and integral with said strip which consists in the steps of raising and partially reversappended ing a portion of the metal, for each projecsions and thereafter reforming said depressions to the desired shape and size.

3. The method offorming a sheet metal strip comprising a multiple series of integral tubular projections from said strip material,

which comprises initially displacing from the plane of the strip an amount of metal sufficient to form each of the desired projections'and simultaneously forming depressions in said displaced portions and displacing said initially -displaced portions in the direction of said depressions to the opposite side of the sheet to form tubular projections from the plane of the sheet of the combined ,1 Y depth of the height of the initially displaced portions and the simultaneously formed depressions.

l. The method of forming integral tubular projections from astrip of sheet material to produce a strip with a continuous series of projections therein, which comprises initially'displacing from the plane of the strip an amount of metal sufficient to form each of the desired projections and simultaneousl forming depressions in said displaced portions, displacing said initially displaced portions to the opposite side of'the sheet to form tubular projections from the plane of the sheet of the combined depth of the height of the initially displaced portions and the simultaneously formed depressions, reforming said tubular projectionsto the desired diameter and depth and punching out the bottom thereof.

5. The method of continuously forming and retaining integral a plurality of tubular projections in multiple rows in a strip of sheet metal comprising the simultaneous raising of portions of the metal sufficient to form each of the entire projections, reversing and displacing the raised portions below the plane of the strip and subsequently reforming the reversed and displaced portions to form the final product without further drawing metal from the strip itself.

In testimony whereof I have afiixed my signature to this specification.

JOHN KARMAZIN. 

